1. Field of the Invention
The invention relates to flow valves. More particularly, the invention relates to valves for use in applications where high purity and low turbulence fluid flow is desirable.
2. Description of the Related Art
In many industrial applications, the control of fluid flow is necessary, and a wide variety of valve designs for performing this control are well known. In some applications, the dispensing of well controlled volumes of pure chemical reagents in liquid or gaseous form is required. Such applications include chemical and pharmaceutical processing, semiconductor manufacture, as well as many others. In these applications, low turbulence and minimal contamination in the fluid distribution process are significant concerns.
Currently available valves, however, generally include internal seals, non-linear flow pathways, and other features that increase the potential for contamination and turbulence. Although a linear fluid path valve without internal seals is described in U.S. Pat. No. 5,848,780 to Miller et al., this valve includes a large number of parts, and requires magnetized metallic elements in the fluid flow stream. Thus, the Miller et al. valve design results in a high manufacturing cost, increased maintenance, and internal components which may be incompatible with the fluid in the valve. Accordingly, what is needed in the art are fluid flow valves which are inexpensive to manufacture, which allow low turbulence flow, and which are less susceptible to leakage or contamination of the flowing fluid.
In one embodiment, the invention comprises a fluid flow valve including a housing defining a fluid flow path. The housing comprises a first portion coupled to at least a second portion of the housing by a deformable segment, wherein the deformable segment includes a plurality of notches, and wherein the first portion is moveable toward and away from the second portion. A poppet is attached to the second portion and positioned in the fluid flow path such that the first portion abuts the poppet to stop fluid flow through the valve when the first portion is moved toward the second portion.
The valve may further comprise a third portion coupled to the first portion by an additional deformable segment having a plurality of notches, wherein the second segment is deformable such that the first portion is moveable toward and away from the third portion.
In an additional aspect of the invention, the valve further comprises one or more sleeves surrounding the housing and isolating air surrounding the deformable segment from ambient conditions.